To solve the problem, we need to use the formula for the volume of a cube, which is given by:
\[ V = s^3 \]
where \( V \) is the volume and \( s \) is the length of a side of the cube. Given that the volume of the cube is 64 cm³, we set up the equation:
\[ s^3 = 64 \]
To find the side length \( s \), we take the cube root of both sides:
\[ s = \sqrt[3]{64} = 4 \text{ cm} \]
Now, we can determine which conclusions are valid among the options provided:
1. **The side length is 4 cm.** - **True**, as we calculated \( s = 4 \) cm.
2. **The side length is 8 cm.** - **False**, as \( s = 4 \) cm.
3. **The expression \( s^2 \), where s represents the side length, was used to solve this problem.** - **False**, as we used \( s^3 \) to find the volume, not \( s^2 \).
4. **Taking the cube root of its volume will determine its side length.** - **True**, as we took the cube root of 64 to find \( s \).
Thus, the correct conclusions are:
- The side length is 4 cm.
- Taking the cube root of its volume will determine its side length.